1. Field of the Invention
The present invention relates to a clamp type contact having a pair of elongate contact pieces adapted to clamp a terminal of an electronic component or electric connector therebetween and to a method of the manufacture of the clamp type contact.
2. Description of the Related Art
Generally, clamp type contacts used in a connector for connecting electronic appliances together are required to have good spring characteristics. A material having a high degree of toughness, such as phosphor bronze, is plated with gold and the result is used as a contact piece. Recently, there is an increasing demand for the miniaturization of contacts and the reduction of an accommodation space for contacts. Therefore, efforts have been made to obtain contact pieces having lengths effective to exhibit elastic displacement and to improve stock utilization as much as possible under the limited conditions by using a blank layout, resulting from the aforementioned demands for miniaturization and reduction.
Heretofore, a pair of opposed contact pieces of a clamp type contact have been formed either by punching a long blank member out of a sheet and bending the long blank member in a U-shaped or by punching two blank members connected through a connection portion out of a sheet and bending the blank members to rise from the connection portion, such as disclosed in Japanese Utility Model Publication No. SHO 52-49978. In either case, it is necessary not only to punch a blank member of at least a length corresponding to the total length of the contact pieces developed, but also to consider the bend allowance for the connection portion of the contact pieces in order to obtain sufficient effective lengths of the contact pieces. Since the reduction in length of the blank member to be punched out of a sheet has its own limit and since the bend allowance constitutes excess material, stock utilization cannot be greatly improved. Furthermore, since the opposed surfaces of the prior art contact pieces have relatively large widths, the recent demand for the miniaturization of contacts is not met.
When a clamp type contact has a pair of contact pieces of the same thickness for clamping a terminal therebetween, since the free ends of the contact pieces have similar frequency characteristics, there is a fair possibility of resonance phenomena occurring through the medium of the clamped terminal due to external vibrations, thereby giving rise to unstable contact between the terminal and the contact pieces.